The two most common nylon fibers, nylon 6,6 and nylon 6, are not resistant to staining by certain acid dyes commonly present in foods and beverages. In the past, these nylon fibers have been made stain-resistant by either treating the fiber surface with an anti-stain chemical (see for example Blyth and Ucci U.S. Pat. No. 4,592,940) or by modifying the polymer (see for example Anton et al., U.S. Pat. No. 5,108,684 or Windley, U.S. Pat. No. 5,155,178). More recently Hoyt and Wilson, European Patent Application No. 574,772, have disclosed a bicomponent multilobal filament having a polyamide core and a hydrophobic polymer sheath. The sheath polymers disclosed include polyesters and polyolefins. Because polyesters and polyolefins are generally incompatible with nylon, sheath-core filaments of polyester-nylon or polyolefin-nylon may have poor mechanical properties and the sheath may separate from the core in some end uses. Therefore, an all-nylon sheath-core stain-resistant filament would be useful.